AWWA ACE68627

This powerpoint presentation begins by providing a brief overview of Cyanobacteria and their toxins, and Microcystin-LR (MC-LR). Topics presented include the following: toxicity of MC-LR; health incidents; regulations; monitoring Cyano-HABs; persistence and decomposition of MCs innatural waters; Cyanobacteria and toxins affecting water treatment; MC-LR treatment-conventional methods; MC-LR treatment-AOTs; synthesis of TiO₂ photocatalysts: challenges; synthesis approach: surfactant-templates; analytical methods for the quantification ofMC-LR#, CYN and detection of intermediates; overall charge of TiO₂ and MC-LR f = (pH); time intervals: MC-LR and intermediates; potential MC-LR sites of hydroxyl radical attack; chemical mechanisms of AOTs; and, mechanistic steps of AOTs. Presentation conclusions indicate that:nanostructured TiO₂ photocatalytic films successfully degraded MC-LRand CYN;identification of 4 positions that HRs generated with TiO₂ photocatalysiscan initially react with MC-L,Sites A, B, C: intermediates where the Adda chain is affected;Site C -- complete removal of the Adda chain; the diene bonds are more susceptible to free radicals (m/z =1029.5),Sites D: intermediates with alternation in the cyclic structure;main mechanistic steps for MC-LR and CYN includedIsomerization,Hydroxylation (Substitution/Addition),Oxidation, andbond cleavage. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2008

Number of Pages:

33

File Size:

1 file , 2.1 MB